The Improvement Of Offline Traffic Guidance Screen Based On ARM9

The rapid development of economy has improved people's standard of living greatly. In the other hand, it requests the situation of urban traffic to achieve a higher level. Now, traffic congestion is a problem most of the cities in our country have to face. To make the enviroment of urban traffic match the rapid economic development, it is necessary to build an intelligent guidance information system of urban traffic.This dissertation is to improve the original guidance system of urban traffic and make its performance more perfect. Firstly, the framework of the system, which consists of the collection and publishment of the guidance information, the network of transmission and the displaying system, is introduced. By analyzing, some problems of the current system are discovered: first, it communicates through PSTN, and too much time is wasted in dialing. Transmission speed is slow, but with high bit error rate. Then, the offline card of the induced screen is TMS320LF2407. As original storage space is limited, FLASH has to be erased frequently. This seriously affects the effect of display. In order to solve the above problems, the improved scheme is designed: the way of communication is changed from PSTN to LAN, communicating by network. The offline card adopts the ARM9 ST2410 development board. This board supports network function. Its FLASH has enough storage space. It supports operating system, which makes the whole system easy to manage and maintain.In this dissertation, the hardware structure of the board is introduced briefly, and then the application of SPI and the working process of DMA are focused on.There are three experiments totally: testing every part of the board, implementing network protocol on ST2410 and sending data to the receiving board through SPI. In addition, some display effects are added before transmission and this makes the content of the screen much more abundant.Through debugging, these experiments are implemented successfully. To simplify the system, the author designed a new board on the basis of the core board S3C2410 of ST2410. The board is manufactured, debugged and integrated into the whole system. The system can work correctly in practice. The experimental data indicates that the performance of the system has been improved greatly, and the new system has significant impact on urban traffic management.